: His character takes a darker turn as he spirals into a drug addiction that jeopardizes his career and relationship with the team.
: The season picks up immediately after the Season 4 finale, with characters like Sam Swarek and Chloe Price fighting for their lives in the hospital after being shot.
: The fallout from the shooting; Andy and Dov handle a diner robbery while off-duty.
: Introduces Duncan Moore ; Oliver begins his tenure as Staff Sergeant.
: For the first time, the original five rookies (Andy, Dov, Gail, Traci, and Chris) are now five-year veterans. Andy McNally takes on a mentoring role as a Training Officer for a new, eager, yet problematic rookie, Duncan Moore .
